Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (0, 1), (1, -1)}.
A151263
Number of walks within N^2 (the first quadrant of Z^2) starting at (0,0) and consisting of n steps taken from {(-1, -1), (-1, 0), (0, -1), (0, 1), (1, -1)}.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =6a(4) =20a(5) =52a(6) =175a(7) =526a(8) =1793a(9) =5841a(10) =20253a(11) =69270a(12) =244522a(13) =862772a(14) =3097566a(15) =11167024a(16) =40692846a(17) =149065293a(18) =550140081a(19) =2040710835a(20) =7613008077a(21) =28530887220a(22) =107416078626a(23) =406033088229
External references
- oeis: A151263